diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/c/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/c/c-parser.c | 54 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/c2x-attr-deprecated-4.c | 13 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/c2x-attr-fallthrough-4.c | 23 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/c2x-attr-maybe_unused-4.c | 13 |
6 files changed, 111 insertions, 2 deletions
diff --git a/gcc/c/ChangeLog b/gcc/c/ChangeLog index 75a44e2..0076e83 100644 --- a/gcc/c/ChangeLog +++ b/gcc/c/ChangeLog @@ -1,5 +1,10 @@ 2019-11-15 Joseph Myers <joseph@codesourcery.com> + * c-parser.c (c_parser_std_attribute_specifier): Diagnose + duplicate standard attributes. + +2019-11-15 Joseph Myers <joseph@codesourcery.com> + * c-decl.c (std_attribute_table): Add maybe_unused. 2019-11-15 Joseph Myers <joseph@codesourcery.com> diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c index 5b290bf..e48760d 100644 --- a/gcc/c/c-parser.c +++ b/gcc/c/c-parser.c @@ -4873,6 +4873,9 @@ c_parser_std_attribute (c_parser *parser) static tree c_parser_std_attribute_specifier (c_parser *parser, bool for_tm) { + bool seen_deprecated = false; + bool seen_fallthrough = false; + bool seen_maybe_unused = false; location_t loc = c_parser_peek_token (parser)->location; if (!c_parser_require (parser, CPP_OPEN_SQUARE, "expected %<[%>")) return NULL_TREE; @@ -4898,8 +4901,55 @@ c_parser_std_attribute_specifier (c_parser *parser, bool for_tm) tree attribute = c_parser_std_attribute (parser); if (attribute != error_mark_node) { - TREE_CHAIN (attribute) = attributes; - attributes = attribute; + bool duplicate = false; + tree name = get_attribute_name (attribute); + tree ns = get_attribute_namespace (attribute); + if (ns == NULL_TREE) + { + /* Some standard attributes may appear at most once in + each attribute list. Diagnose duplicates and remove + them from the list to avoid subsequent diagnostics + such as the more general one for multiple + "fallthrough" attributes in the same place (including + in separate attribute lists in the same attribute + specifier sequence, which is not a constraint + violation). */ + if (is_attribute_p ("deprecated", name)) + { + if (seen_deprecated) + { + error ("attribute %<deprecated%> can appear at most " + "once in an attribute-list"); + duplicate = true; + } + seen_deprecated = true; + } + else if (is_attribute_p ("fallthrough", name)) + { + if (seen_fallthrough) + { + error ("attribute %<fallthrough%> can appear at most " + "once in an attribute-list"); + duplicate = true; + } + seen_fallthrough = true; + } + else if (is_attribute_p ("maybe_unused", name)) + { + if (seen_maybe_unused) + { + error ("attribute %<maybe_unused%> can appear at most " + "once in an attribute-list"); + duplicate = true; + } + seen_maybe_unused = true; + } + } + if (!duplicate) + { + TREE_CHAIN (attribute) = attributes; + attributes = attribute; + } } if (c_parser_next_token_is_not (parser, CPP_COMMA)) break; diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 997096c..4376337 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2019-11-15 Joseph Myers <joseph@codesourcery.com> + + * gcc.dg/c2x-attr-deprecated-4.c, gcc.dg/c2x-attr-fallthrough-4.c, + gcc.dg/c2x-attr-maybe_unused-4.c: New tests. + 2019-11-15 Paolo Carlini <paolo.carlini@oracle.com> * g++.dg/warn/Walways-true-1.C: Check locations too. diff --git a/gcc/testsuite/gcc.dg/c2x-attr-deprecated-4.c b/gcc/testsuite/gcc.dg/c2x-attr-deprecated-4.c new file mode 100644 index 0000000..ce6615b --- /dev/null +++ b/gcc/testsuite/gcc.dg/c2x-attr-deprecated-4.c @@ -0,0 +1,13 @@ +/* Test C2x deprecated attribute: duplicates. */ +/* { dg-do compile } */ +/* { dg-options "-std=c2x -pedantic-errors" } */ + +[[deprecated, __deprecated__]] int a; /* { dg-error "can appear at most once" } */ +[[__deprecated__, deprecated("message")]] int b; /* { dg-error "can appear at most once" } */ +int c [[deprecated("message"), deprecated]]; /* { dg-error "can appear at most once" } */ +[[deprecated, deprecated]]; /* { dg-error "can appear at most once" } */ +/* { dg-warning "ignored" "ignored" { target *-*-* } .-1 } */ + +/* Separate attribute lists in the same attribute specifier sequence, + with the same attribute in them, are OK. */ +[[deprecated]] [[deprecated]] int d [[deprecated]] [[deprecated]]; diff --git a/gcc/testsuite/gcc.dg/c2x-attr-fallthrough-4.c b/gcc/testsuite/gcc.dg/c2x-attr-fallthrough-4.c new file mode 100644 index 0000000..75aceff --- /dev/null +++ b/gcc/testsuite/gcc.dg/c2x-attr-fallthrough-4.c @@ -0,0 +1,23 @@ +/* Test C2x fallthrough attribute: duplicates. */ +/* { dg-do compile } */ +/* { dg-options "-std=c2x -pedantic-errors" } */ + +int +f (int a) +{ + switch (a) + { + case 1: + a++; + [[fallthrough, __fallthrough__]]; /* { dg-error "can appear at most once" } */ + case 2: + a++; + /* Separate attribute lists in the same attribute specifier + sequence, with the same attribute in them, are OK (but + receive a warning). */ + [[fallthrough]] [[fallthrough]]; /* { dg-warning "specified multiple times" } */ + case 3: + a++; + } + return a; +} diff --git a/gcc/testsuite/gcc.dg/c2x-attr-maybe_unused-4.c b/gcc/testsuite/gcc.dg/c2x-attr-maybe_unused-4.c new file mode 100644 index 0000000..ae7e1dc --- /dev/null +++ b/gcc/testsuite/gcc.dg/c2x-attr-maybe_unused-4.c @@ -0,0 +1,13 @@ +/* Test C2x maybe_unused attribute: duplicates. */ +/* { dg-do compile } */ +/* { dg-options "-std=c2x -pedantic-errors" } */ + +[[maybe_unused, __maybe_unused__]] int a; /* { dg-error "can appear at most once" } */ +[[__maybe_unused__, maybe_unused]] int b; /* { dg-error "can appear at most once" } */ +int c [[maybe_unused, maybe_unused]]; /* { dg-error "can appear at most once" } */ +[[maybe_unused, maybe_unused]]; /* { dg-error "can appear at most once" } */ +/* { dg-warning "ignored" "ignored" { target *-*-* } .-1 } */ + +/* Separate attribute lists in the same attribute specifier sequence, + with the same attribute in them, are OK. */ +[[maybe_unused]] [[maybe_unused]] int d [[maybe_unused]] [[maybe_unused]]; |